No Display So Bike Won't power Up

[Rider 99]

I have recently built a Dengfu E10 with a Bafang M560 motor system with a C245 V3 display and controller unit.

The bike has worked perfectly for the ten or so rides I've done on it since completing the build (I absolutely love the bike and miss riding it). However the last time I rode it, I didn't power on the display until I was about to start the return leg of my ride, but the display wouldn't light up. I assumed the battery may have been jolted at some point resulting in a loose connection so I removed the battery then put it back in, but this unfortunately made no difference so I had to pedal home with no assistance which was hard work but not the end of the world.

Since then I've done some basic diagnostics and can confirm the battery, power switch with associated wiring is working fine as there is 52v at the motor input XT60 connector that is switchable via the power switch, which is good news. I was unable to check the IT3 cable that runs from the motor to the display unit due to the pins being so small and I don't have a break out cable that I could connect to the motor that would allow me to confirm that the motor is providing 52v to the display.

I strongly suspect that the display may be faulty as it controls all the motor functions from that point on providing it has a power supply from the motor. Of course it could be a break in the IT3 cable which I can't test for reasons mentioned above, but as the motor system was working perfectly for a while I think this would be unlikely.

I've posted this in the hope that someone else may have had this or a similar problem before and can advise on if my diagnosis and thought process is correct and if so did replacing the display unit resolve their issue. Any help would be greatly appreciated.... Many thanks in advance.

 

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Many hub drive controllers carry battery voltage levels on the pin #1 leading to the display and when this is connected/shorted to pin #2 (battery lock) will turn on the bike system with basic throttle only control. no pas or speed limits tho with a 52v battery pack perhaps your not bothered by the regs. a '$2 ebay special bike computer' ( similar to the £30 job i bought in the 90's) can provide a speedo and odometer.

I am unsure if this will apply to your mid drive with its internal controller? it could even cause damage ?? a google of your bikes cable pinouts may reveal more with its naming conventions.

 

[Rider 99]

Thanks for sharing your thoughts.

I'll take your advice on finding out what the motor pin outs are and purchase an IT1 cable with the view of cutting off one end to make a break out lead so I can check what voltages the motor is outputting. If my suspicions are correct and the display unit is indeed faulty.... then I'll purchase a replacement display unit which should hopefully resolve the issue.